Miniature Sound Generator

Abstract

A miniature sound generator is disclosed. The miniature sound generator includes: a vibration system; a magnetic circuit system including a permanent magnet accommodated in a magnetic bowl and a pole piece located on the permanent magnet; and a housing for accommodating and fixing the vibration system. The permanent magnet includes a first through-hole, the pole piece has a second through-hole, and the magnetic bowl includes a blind hole.

What is claimed is: 
     
         1 . A miniature sound generator, comprising:
 a vibration system;   a magnetic circuit system including a permanent magnet accommodated in a magnetic bowl and a pole piece located on the permanent magnet,   a housing for accommodating and fixing the vibration system; wherein   the permanent magnet includes a first through-hole, the pole piece has a second through-hole, and the magnetic bowl includes a blind hole.   
     
     
         2 . The miniature sound generator as described in  claim 1 , wherein the permanent magnet is located between the magnetic bowl and the pole piece, and the first through-hole is located between the second through-hole and the blind hole. 
     
     
         3 . The miniature sound generator as described in  claim 1 , wherein a diameter of the second through-hole is greater than a diameter of the first through-hole. 
     
     
         4 . The miniature sound generator as described in  claim 1 , wherein a diameter of the blind hole is not smaller than a diameter of the first through-hole. 
     
     
         5 . The miniature sound generator as described in  claim 1 , wherein the first through-hole, the second through-hole and the blind hole are cylindrical, and the first through-hole, the second through-hole and the blind hole are coaxial with each other. 
     
     
         6 . The miniature sound generator as described in  claim 1 , wherein the first through-hole, the second through-hole and the blind hole are different in shape, and central axis of the first through-hole, the second through-hole and the blind hole are coaxial with each other. 
     
     
         7 . The miniature sound generator as described in  claim 1 , wherein the first through-hole and the second through-hole penetrate the permanent magnet and the pole piece along a thickness direction of the permanent magnet and the pole piece, and a depth of the blind hole is half of a thickness of the magnetic bowl. 
     
     
         8 . The miniature sound generator as described in  claim 1 , wherein the first through-hole and the second through-hole are located respectively at a center of the permanent magnet and the pole piece. 
     
     
         9 . A miniature sounder generator including:
 a vibration system;   a magnetic circuit system including a permanent magnet and a pole piece accommodated in a magnetic bowl;   a housing for accommodating and fixing the vibration system and the magnetic circuit system therein; wherein   the permanent magnet and the pole piece are provided with a first cavity, and the magnetic bowl is provided with a blind hole.   
     
     
         10 . The miniature sound generator as described in  claim 9 , wherein a second cavity is provided and located between the magnetic bowl and the permanent magnet for communicating with the first cavity.